2,2-Bis(haloalkenyl)-1-cyano-1-alkoxycarbonylethylene fungicides

ABSTRACT

The 1,1-bis(haloalkenyl)-1-cyano-1-alkoxy-carbonylethylene compounds of this invention are effective fungicides. Additionally, some of the compounds of this invention are especially effective against Grape Downy Mildew and Rice Blast.

BACKGROUND OF THE INVENTION

With the world more dependent for food on an ever decreasing amount ofcultivated land, it is necessary to develop fungicides which protectcrops from fungicidal destruction.

U.S. Pat. No. 3,761,596 discloses ethylbis(allylthio)methylidenemalonates and chloro analogs thereof asfungicidal.

U.S. Pat. No. 4,007,279 discloses 2,3-dicyano-5,6-dihydro-p-dithiin andits 5-alkyl derivatives as fungicidal.

SUMMARY OF THE INVENTION

The compounds of the present invention are represented by the formula:##STR1## wherein A. R and R¹ are independently

1. lower alkenyl substituted with 1 to 3 of the same or differenthalogens, or

2. lower alkynyl substituted with 1 to 3 of the same or differenthalogens;

B. R² and R³ are independently

1. hydrogen or

2. lower alkyl; and

C. R⁴ is lower alkyl.

Among other factors, the present invention is based on my finding thatthe compounds of this invention are effective fungicides. Additionally,the compounds of this invention are especially effective against GrapeDowny Mildew and Rice Blast.

Due to their superior fungicidal activity, preferred R and R¹ groups arevinyl substituted with 1 to 3 halogens.

Particularly preferred R and R¹ groups include the vinyl groupssubstituted with 1 to 2 halo atoms.

Preferred halo atoms are chloro and bromo.

Most preferably, R and R¹ are mono- and dichlorinated vinyl groups.

Preferably, R² and R³ are hydrogen.

Definitions:

As used herein, the following terms have the following meanings, unlessexpressly stated to the contrary.

The term "alkyl" refers to both straight- and branched-chain alkylgroups. The term "lower alkyl" refers to both straight- andbranched-chain alkyl groups having a total of from 1 through 6 carbonatoms and includes primary, secondary, and tertiary alkyl groups.Typical lower alkyls include, for example, methyl, ethyl, n-propyl,isopropyl, n-butyl, t-butyl, n-hexyl, and the like.

The term "alkenyl" refers to unsaturated alkyl groups having a doublebond (e.g., CH₃ CH═CH(CH₂)₂ --,) and includes both straight- andbranched-chain alkenyl groups.

The term "lower alkenyl" groups refers to alkenyl groups having from 2through 6 carbon atoms. Typical lower alkenyl groups include, forexample, ethylene, but-3-enyl, hex-4-enyl, 2-methylpent-4-enyl, and thelike.

The term "alkynyl" refers to unsaturated alkyl groups having a triplebond (e.g., CH₃ C.tbd.C(CH₂)₂ --) and includes both straight- andbranched-chain alkynyl groups.

The term "lower alkynyl" refers to alkynyl groups having from 2 through6 carbon atoms and includes, for example, but-3-ynyl, hex-4-ynyl,3-methylpent-4-ynyl, and the like.

The term "halo" or "halogen atom" refers to the groups fluoro, chloro,bromo and iodo.

The term "thioallyl" refers to the group: ##STR2## with the conventionalnumbering system employed. Thus, the term "thio-3'-chloroallyl" refersto the group:

    --SCH.sub.2 CH═CHCl.

The term"1-cyano-1-ethoxycarbonyl-2-(thio-2'-bromoallyl)-2-(thio-3'-chloroallyl)ethylene"refers to the group: ##STR3##

DETAILED DESCRIPTION OF THE INVENTION

The compounds of this invention are prepared according to the followingsynthetic scheme: ##STR4## wherein R, R¹, R², R³ and R⁴ are as definedabove and X is a halogen.

The compounds of Formula I wherein R and R¹ are identical to each otherand R² and R³ are identical to each other are conveniently prepared asshown in Reactions (1) and (2) above.

Reaction (1) is conveniently conducted by adding 2 to 2.5 equivalents ofan inorganic base to the appropriate reagent, II. The reaction is donein the liquid phase employing an inert organic solvent such as dioxane,tetrahydrofuran, diethyl ether, and the like. Suitable inorganic basesinclude, for instance, potassium hydroxide, sodium carbonate, potassiumcarbonate, and the like. Preferably, the reaction employs pulverizedpotassium hydroxide as the base in a dioxane medium. 1 to 2.5equivalents of carbon disulfide, IV, is then added to the system. Thereaction is generally conducted at from 0° to 100° C., althoughpreferably at from 5° to 40° C. and is generally complete from within 1to 24 hours. Reaction pressure is not critical and for convenience, thereaction is generally conducted at atmospheric pressure. The product, V,is then isolated by conventional procedures such as extraction,filtration, chromatography, distillation, or alternatively is used inReaction (2) without purification and/or isolation.

Reaction (2) is conducted by adding 2 to 2.5 equivalents of theappropriate reagent, VI, to V. The reaction is conducted in the liquidphase employing an inert organic solvent such as dimethylformamide,toluene, methanol, and the like. Reaction pressure is not critical andfor convenience, the reaction is generally conducted at atmosphericpressure. The reaction is generally conducted at from -10° to 50° C.,although preferably at from 20° to 40° C. and is generally complete fromwithin 1 to 48 hours. The product, I, is isolated by conventionalprocedures such as extraction, filtration, chromatography, distillation,and the like.

The synthesis of compounds of this invention wherein R and R¹ are notidentical or R² and R³ are not identical is depicted in Reactions (3),(4) and (5).

Reaction (3) is conveniently conducted by adding an essentiallyequimolar amount of an inorganic base to the appropriate reagent, II.The reaction is done in the liquid phase employing an inert organicsolvent such as dioxane, tetrahydrofuran, dimethylformamide, and thelike. Suitable inorganic bases include, for instance, potassiumhydroxide, sodium carbonate, potassium carbonate, and the like.Preferably, the reaction employs pulverized potassium hydroxide as thebase in a dimethylformamide medium. 1 to 2.5 equivalents of carbondisulfide, IV, is then added to the system. The reaction is generallyconducted at from -20° to 50° C., although preferably at from -5° to 20°C. and is generally complete from within 1 to 24 hours. Reactionpressure is not critical and for convenience, the reaction is generallyconducted at atmospheric pressure. The product, VII, is isolated byconventional procedures such as extraction, filtration, chromatography,distillation, and the like. Alternatively and preferably, the product,VII, is used directly in Reaction (4) using the same vessel and solvent.

Reaction (4) is conducted by adding an essentially equimolar amount ofthe appropriate reagent, VI, to VII. The reaction is conducted in theliquid phase employing an inert organic solvent such asdimethylformamide, dioxane, and the like. Preferably, the reactionsolution is the same as was employed in Reaction (3) with theappropriate reagent VI merely added to the system after completion ofReaction (3). Reaction pressure is not critical and for convenience, thereaction is generally conducted at atmospheric pressure. The reaction isgenerally conducted at from 0° C. to 100° C., although preferably atfrom 15° to 25° C. and is generally complete from within 1 to 24 hours.The product, VIII, is isolated by conventional procedures such asextraction, filtration, chromatography, distillation, and the like.Alternatively and preferably, the product, VIII, is used directly inReaction (5) using the same vessel and solvent.

Reaction (5) is conducted by adding an essentially equimolar amount ofan inorganic base to VIII. The reaction is conducted in the liquid phaseemploying an inert organic solvent such as dimethylformamide, dioxane,and the like. Preferably, the base is added at from 0° to 5° C. to thesame solution as was employed in Reaction (4) with the appropriate basemerely added to the cooled system after completion of Reaction (4).Suitable inorganic bases include, for instance, potassium hydroxide,sodium carbonate, potassium carbonate, and the like. Preferably, thereaction employs pulverized potassium hydroxide as the base. Afteraddition of the base, an essentially equimolar amount of the appropriatereagent, IX, is added. This reaction is generally conducted at from 0°to 100° C. and is generally complete from within 1 to 48 hours. Reactionpressure is not critical and for convenience, the reaction is generallyconducted at atmospheric pressure. The product, I, is then isolated byconventional procedures such as extraction, filtration, chromatography,distillation, and the like.

Reactions (1), (3) and (5) involve the addition of a solid base to anorganic solvent. In order to facilitate reaction completion, aphase-transfer catalyst is preferably employed in these reactions to aidin the transfer of the solid base into the organic solvent. Preferredcatalysts include, for instance, tetraalkylammonium halides. Aparticularly preferred catalyst is tetra-n-butylammonium bromide. Ingeneral, 0.025 equivalents of the catalyst have been found sufficient toaccomplish the catalytic effect desired.

Alternatively, if the base employed is in an aqueous solution, aphase-transfer catalyst is employed to facilitate transfer from theaqueous phase to the organic phase.

Reactions (2) and (4) involve adding a potassium thiolate to an organicmedium. Preferably, in order to speed the time required for reaction, acatalytic amount (˜0.025 equivalents) of a phase-transfer catalyst isadded. Catalysts such as tetraalkylammonium halide salts are preferred.

Utility:

The compounds of this invention are useful for controlling fungi.Additionally, some of the compounds of this invention are useful incontrolling leaf blights caused by such organisms as Phytophthorainfestans conidia, Alternaria solani conidia, Septoria apii, downymildew caused by organisms such as Plasmopara viticola, and other fungalinfections caused by organisms such as Piricularia oryzae and Uromycesphaseoli tipica.

However, some fungicidal compounds of the invention may be morefungicidally active than others against particular fungi. Table II listsa summary of activity against some particular fungi for severalcompounds of this invention.

When used as fungicides, the compounds of the invention are applied infungicidally effective amounts to fungi and/or their habitats, such asvegetative hosts and non-vegetative hosts, e.g., animal products. Theamount used will, of course, depend on several factors such as the host,the type of fungus and the particular compound of the invention. As withmost pesticidal compounds, the fungicides of the invention are notusually applied full strength, but are generally incorporated withconventional, biologically inert extenders or carriers normally employedfor facilitating dispersion of active fungicidal compounds, recognizingthat the formulation and mode of application may affect the activity ofthe fungicide. Thus, the fungicides of the invention may be formulatedand applied as granules, as powdery dusts, as wettable powders, asemulsifiable concentrates, as solutions, or as any of several otherknown types of formulations, depending on the desired mode ofapplication.

Wettable powders are in the form of finely divided particles whichdisperse readily in water or other dispersant. These compositionsnormally contain from about 5% to 80% fungicide, and the rest inertmaterial, which includes dispersing agents, emulsifying agents andwetting agents. The powder may be applied to the soil as a dry dust, orpreferably as a suspension in water. Typical carriers include fuller'searth, kaolin clays, silicas, and other highly absorbent, readilywettable, inorganic diluents. Typical wetting, dispersing or emulsifyingagents include, for example: the aryl and alkylaryl sulfonates and theirsodium salts; alkylamide sulfonates, including fatty methyl taurides;alkylaryl polyether alcohols, sulfated higher alcohols, and polyvinylalcohols; polyethylene oxides, sulfonated animal and vegetable oils;sulfonated petroleum oils, fatty acid esters of polyhydric alcohols andthe ethylene oxide addition products of such esters; and the additionproducts of long-chain mercaptans and ethylene oxide. Many other typesof useful surface-active agents are available in commerce. Thesurface-active agent, when used, normally comprises from 1% to 15% byweight of the fungicidal composition.

Dusts are freely flowing admixtures of the active fungicide with finelydivided solids such as talc, natural clays, kieselguhr, pyrophyllite,chalk, diatomaceous earths, calcium phosphates, calcium and magnesiumcarbonates, sulfur, lime, flours, and other organic and inorganic solidswhich act as dispersants and carriers for the toxicant. These finelydivided solids have an average particle size of less than about 50microns. A typical dust formulation useful herein contains 75% silicaand 25% of the toxicant.

Useful liquid concentrates include the emulsifiable concentrates, whichare homogeneous liquid or paste compositions which are readily dispersedin water or other dispersant, and may consist entirely of the fungicidewith a liquid or solid emulsifying agent, or may also contain a liquidcarrier such as xylene, heavy aromatic naphthas, isophorone, and othernonvolatile organic solvents. For application, these concentrates aredispersed in water or other liquid carrier, and are normally applied asa spray to the area to be treated.

Other useful formulations for fungicidal applications include simplesolutions of the active fungicide in a dispersant in which it iscompletely soluble at the desired concentration, such as acetone,alkylated naphthalenes, xylene, or other organic solvents. Granularformulations, wherein the fungicide is carried on relatively courseparticles, are of particular utility for aerial distribution or forpenetration of cover-crop canopy. Pressurized sprays, typically aerosolswherein the active ingredient is dispersed in finely divided form as aresult of vaporization of a low-boiling dispersant solvent carrier, suchas the Freons, may also be used. All of those techniques for formulatingand applying fungicides are well known in the art.

The percentages by weight of the fungicide may vary according to themanner in which the composition is to be applied and the particular typeof formulation, but in general comprise 0.5% to 95% of the toxicant byweight of the fungicidal composition.

The fungicidal compositions may be formulated and applied with otheractive ingredients, including other fungicides, insecticides,nematocides, bactericides, plant-growth regulators, fertilizers, etc.

A further understanding of the invention can be had in the followingnon-limiting Examples. Wherein, unless expressly stated to the contrary,all temperatures and temperature ranges refer to the centigrade systemand the term "ambient" or "room temperature" refers to about 20° to 25°C. The term "percent" refers to weight percent and the term "mol" or"mols" refers to gram mols. The term "equivalent" refers to a reagentequal in mols, to the mols of the preceding or succeeding reactantrecited in that example in terms of finite mols or finite weight orvolume. Also, unless expressly stated to the contrary, geometric isomerand racemic mixtures are used as starting materials and correspondinglyisomer mixtures are obtained as products. Also, unless expressly statedto the contrary, mixtures of E and Z isomers are generated wheneverpossible and are not separated.

Compounds which were prepared in accordance with Examples 1 to 4 beloware listed in Table I.

EXAMPLE 1 Preparation of1-cyano-1-methoxycarbonyl-2,2-bis(thio-3'-chloroallyl)ethylene

(a) To a suspension of 708.6 gm of 85% potassium hydroxide flakes in 6liters of methylene chloride, maintained at 5° C. to 12° C., was added48.3 gm of tetra-n-butylammonium bromide. The system was allowed to cometo room temperature (19° to 20° C.) and then 606.7 gm of 98%α-cyanoacetic acid methyl ester was added over 5 minutes. Carbondisulfide, 1089 gm, was then added over 35 minutes. After addition, thesystem was gradually heated to reflux over 90 minutes and maintained atreflux for an additional 40 minutes. Afterwards, the system was stirredat the ambient temperature for 2 hours and 20 minutes and then leftstanding for 16 hours. The product, which had precipitated from solutionas a yellow gum, was collected, washed first with methanol and then withmethylene chloride and air dried to yield 1098 gm (73% yield) of thedipotassium salt. Following the same procedure, the above reaction wasrepeated twice yielding 1042 gm (69%) and 1038 gm (69%).

(b) 2010 gm of the dipotassium salt was suspended in 5.33 liters ofmethanol. 1776 gm of trans-1,3-dichloropropene was then added at roomtemperature. After addition, there was a slow exotherm to 38° C., atwhich time the system was maintained for 45 minutes at 38° C. to 40° C.by external cooling. Afterwards, as the temperature fell, the ice bathwas removed and the system stirred at the ambient temperature for anadditional 20 hours. The reaction was then stopped and the system pouredinto 11 liters of water. The product was extracted with methylenechloride. The organic solution was washed first with water and thenbrine. The organic solution was dried over magnesium sulfate, filteredand the methylene chloride then removed by stripping to yield 2058 gm ofthe 1-cyano-1-methoxycarbonyl-2,2-bis(thio-3'-chloroallyl)ethylene as areddish brown oil. Listed as Compound No. 6.

EXAMPLE 2 Preparation of1-cyano-1-t-butoxycarbonyl-2,2-bis(thio-2,3-dichloroallyl)ethylene

To a suspension of 13.18 gm of pulverized potassium hydroxide in 150 mlof dioxane was added 14.1 gm of α-cyanoacetic acid t-butyl ester over 1hour. Afterwards, 12 ml of carbon disulfide was added. The system wasstirred at room temperature for 18 hours and then the system was dilutedwith 150 ml of ether. The resulting precipitate was filtered and washedwith ether. The product was then suspended in 200 ml ofdimethylformamide. 33.44 gm of 1,2,3-trichloropropene was slowly addedto the system at from 0° to 10° C. The system was stirred at 50° C. for20 hours and the solution then poured into water. The product wasextracted with ethyl ether. The product was separated and purified bycolumn chromatography using silica gel and 20% ethyl acetate-hexane asthe elutant. The product was isolated and the solvent removed to givethe 1-cyano-1-t-butoxycarbonyl-2,2-bis(thio-2,3-dichloroallyl)ethyleneas a yellow oil. Listed as Compound No. 2 in Table I.

EXAMPLE 3 Preparation of1-cyano-1-isopropoxycarbonyl-2,2-bis(thio-2'-chloroallyl)ethylene

To a suspension of 13.18 gm of pulverized potassium hydroxide in 150 mlof dioxane was added 12.7 gm of α-cyanoacetic isopropyl ester over 1hour. Afterwards, 10 ml of carbon disulfide was added. The system wasstirred at room temperature for 18 hours and then the system was dilutedwith 150 ml of ether. The resulting precipitate was filtered and washedwith ether. The product was then suspended in 150 ml ofdimethylformamide. 27.7 gm of 2,3-dichloropropene was slowly added tothe system at from 0° to 10° C. The system was stirred at 20° C. for 18hours and the solution then poured into water. The product was extractedwith ethyl acetate. The product was separated and purified by columnchromatography using silica gel and 20% ethyl acetate-hexane as theelutant. The product was isolated and the solvent removed to give the1-cyano-1-isopropoxycarbonyl-2,2-bis(thio-2'-chloroallyl)ethylene as abrown oil. Listed as Compound No. 10 in Table I.

EXAMPLE 4 Preparation of1-cyano-1-methoxycarbonyl-2-(thio-2-bromoallyl)-2-(thio-3-chloroallyl)ethylene

(a) 17.8 gm of α-cyanoacetic acid methyl ester in 30 ml ofdimethylformamide is added dropwise at 0° C. to a suspension of 13.6 gmof pulverized potassium hydroxide in 150 ml of dimethylformamide. Themixture is stirred at this temperature for 30 minutes. Afterwards, 15 mlof carbon disulfide is slowly added to the system. The system is warmedto room temperature and stirred there for 3 hours. 40.0 gm of2,3-dibromoprop-1-ene is then added to the system. The system is stirredat room temperature for 16 hours to give the1-cyano-1-methoxycarbonyl-dithioacetic acid 2-bromoallyl ester.

(b) To the system containing the 1-cyano-1-methoxycarbonyl-dithioaceticacid 2-bromoallyl ester is added 13.6 gm of pulverized potassiumhydroxide at 0° C. The system is stirred for 1/2 hour and then 22.1 gmof 1,3-dichloropropene is added. The system is stirred for 6 hours andthen poured into water. The product is extracted with ether and theethereal extract first washed with sodium bicarbonate solution and thenwith brine. The ethereal solution is then dried over magnesium sulfateand the ether removed by stripping to give a crude product. The productis separated and purified by column chromatography to give the1-cyano-1-methoxycarbonyl-2-(thio-2-bromoallyl)-2-(thio-3-chloroallyl)ethyleneproduct.

Other compounds which are prepared in accordance with Examples 1 to 4above include, for instance:

1-cyano-1-methoxycarbonyl-2,2-bis(thio-3'-chloroallyl)ethylene;

1-cyano-1-ethoxycarbonyl-2,2-bis(thio-3'-bromoallyl)ethylene;

1-cyano-1-n-propoxycarbonyl-2,2-bis(thio-3'-bromoallyl)ethylene;

1-cyano-1-t-butoxycarbonyl-2,2-bis(thio-3'-chloroallyl)ethylene;

1-cyano-1-methoxycarbonyl-2-(thio-3'-chloroallyl)-2-(thio-2'-bromoallyl)ethylene;

1-cyano-1-ethoxycarbonyl-2-(thio-2',3'-dichloroallyl)-2-(thio-2',3'-dibromoallyl)ethylene;

1-cyano-1-methoxycarbonyl-2,2-bis[thio-(1'-methyl-2'-chloroallyl)]ethylene;

1-cyano-1-hexoxycarbonyl-2,2-bis[thio-(1'-methyl-2-bromoallyl)]ethylene;and

1-cyano-1-t-butoxy-2,2-bis[thio-(1'-n-propyl-2-chloroallyl)]ethylene.

EXAMPLE 5 Bean Powdery Mildew

The compounds of the invention were tested for the control of the BeanPowdery Mildew organism Erysiphe polygoni. Seedling bean plants weresprayed with a 250 ppm solution of the test compound in acetone, waterand a nonionic emulsifier. The sprayed plants were then inoculated 1 daylater with the organism. The plants were maintained for 10 days attemperatures of 68° F. at night with daytime temperatures of 72° to 80°F.; relative humidity was maintained at 40% to 60%. The percent diseasecontrol provided by a given test compound was based on the percentdisease reduction relative to the untreated check plants. The resultsare tabulated in Table II.

EXAMPLE 6 Tomato Late Blight

Compounds of the invention were tested for the preventative control ofthe Tomato Late Blight organism Phytophthora infestans. Five- tosix-week-old tomato (cultivar Bonny Best) seedlings were used. Thetomato plants were sprayed with a 250 ppm suspension of the testcompound in acetone, water and a nonionic emulsifier. The sprayed plantswere then inoculated 1 day later with the organism, placed in anenvironmental chamber and incubated at 66° to 68° F. and 100% relativehumidity for at least 16 hours. Following the incubation, the plantswere maintained in a greenhouse for approximately 7 days. The percentdisease control provided by a given test compound was based on thepercent disease reduction relative to untreated check plants. Theresults are tabulated in Table II. In Table II, the test concentrationis 250 ppm unless otherwise indicated by the figures in parentheses.

EXAMPLE 7 Celery Late Blight

The Celery Late Blight tests were conducted using celery (Utah) plants11 weeks old. The Celery Late Blight organism was Septoria apii. Thecelery plants were sprayed with 250 ppm solutions of the candidatetoxicant mixed with acetone, water and a nonionic emulsifier. The plantswere then inoculated with the organism and placed in an environmentalchamber and incubated at 66° to 68° F. in 100% relative humidity for anextended period of time (approximately 48 hours). Following theincubation, the plants were allowed to dry and then were maintained in agreenhouse for approximately 14 days. The percent disease controlprovided by a given candidate toxicant is based on the percent diseasereduction relative to untreated check plants. The results are reportedin Table II.

EXAMPLE 8 Tomato Early Blight

Compounds of the invention were tested for the control of the TomatoEarly Blight organism Alternaria solani conidia. Tomato (variety BonnyBest) seedlings of 6- to 7-weeks old were used. The tomato plants weresprayed with a 250 ppm solution of the test compound in anacetone-and-water solution containing a small amount of a nonionicemulsifier. The sprayed plants were inoculated 1 day later with theorganism, placed in an environmental chamber and incubated at 66° to 68°F. and 100% relative humidity for 24 hours. Following the incubation,the plants were maintained in a greenhouse for about 12 days. Percentdisease control was based on the percent disease development onuntreated check plants. The compounds tested and the results aretabulated in Table II.

EXAMPLE 9 Grape Downy Mildew

The compounds of the invention were tested for the control of the GrapeDowny Mildew organism Plasmopara viticola. Detached leaves, between 70and 85 mm in diameter, 7-week-old Vitis vinifera cultivar Emperor grapeseedlings were used as hosts. The leaves were sprayed with a 250 ppmsolution of the test compound in acetone. The sprayed leaves were dried,inoculated with a spore suspension of the organism, placed in a humidenvironmental chamber and incubated at 66° to 68° F. and about 100%relative humidity. After incubation for 2 days, the plants were thenheld in a greenhouse 7 to 9 days; then the amount of disease control wasdetermined. The percent disease control provided by a given testcompound was based on the percent disease reduction relative tountreated check plants. The results are tabulated in Table II.

EXAMPLE 10 Leaf Rust

The Leaf Rust test was made using pinto beans. The pathogen was Uromycesphaseoli tipica. The pinto bean plants were sprayed with a 250 ppmsolution of the test compound in an acetone-water mixture containing anonionic emulsifier. The treated plants were inoculated thereafter withthe pathogen and then incubated in an environmental chamber forapproximately 20 hours at 100% relative humidity and a temperature of68° to 70° F. The plants were then removed from the chamber, allowed todry, and then maintained in a greenhouse at a 60% to 80% relativehumidity. The rate of infection on the leaves was made after about 14days. The percent disease control provided by a given test compound wasbased on the percent disease reduction relative to untreated checkplants. The results are reported in Table II.

EXAMPLE 11 Rice Blast

Compounds of this invention were tested for control of the Rice Blastorganism Piricularia oryzae, using 10- to 14-day-old rice plant seedings(Calrose M-9 variety). Seedling plants were sprayed with a 625 ppmsolution of the test compound in acetone, water and a non-ionicemulsifier (ORTHO X-77 spreader). The sprayed plants were inoculated 1day later with the organism in an environmental chamber. Afterinoculation, the plants were kept in an environmental chamber for about48 hours under conditions of about 72° to 75° F. and about 100% relativehumidity. Following the incubation period, the plants were placed in agreenhouse with a temperature of about 72° F. and maintained with bottomwatering for about 12 to 16 days. The percent disease control providedby a given test compound is based on a comparison of the percentagedisease relative to the percent disease development on the untreatedcheck plants. ##EQU1## The results are tabulated in Table II.

                                      TABLE I                                     __________________________________________________________________________    COMPOUNDS OF THE FORMULA                                                       ##STR5##                                                                                            ANALYSIS                                               Compound               Carbon Hydrogen                                                                             Nitrogen                                 No.   R      R.sup.1   Calc.                                                                            Found                                                                             Calc.                                                                            Found                                                                             Calc.                                                                            Found                                                                             Form                              __________________________________________________________________________    1     C.sub.2 H.sub.5                                                                      CH.sub.2 CHCHCl                                                                         42.61                                                                            42.33                                                                             3.87                                                                             4.00                                                                              4.14                                                                             4.37                                                                              oil                               2     C(CH.sub.3).sub.3                                                                    CH.sub.2 CClCHCl                                                                        38.64                                                                            37.76                                                                             3.47                                                                             3.46                                                                              3.22                                                                             3.19                                                                              oil                               3     C(CH.sub.3).sub.3                                                                    CH.sub.2 CHCHCl                                                                         45.90                                                                            44.72                                                                             4.68                                                                             4.95                                                                              3.82                                                                             3.82                                                                              oil                               4     CH.sub.2 CH.sub.3                                                                    CH.sub.2 CClCHCl                                                                        35.39                                                                            36.54                                                                             2.72                                                                             2.86                                                                              3.44                                                                             3.85                                                                              oil                               5     CH.sub.3                                                                             CH.sub.2 CClCH.sub.2                                                                    40.75                                                                            41.25                                                                             3.41                                                                             3.45                                                                              4.31                                                                             4.66                                                                              oil                               6     CH.sub.3                                                                             CH.sub.2 CHCHCl                                                                         40.75                                                                            41.67                                                                             3.41                                                                             3.51                                                                              4.31                                                                             4.55                                                                              oil                               7     CH.sub.3                                                                             CH.sub.2 CClCHCl                                                                        33.60                                                                            33.10                                                                             2.30                                                                             2.28                                                                              3.50                                                                             3.74                                                                              oil                                      ##STR6##                                                                             ##STR7## 44.32                                                                            44.39                                                                             4.29                                                                             4.30                                                                              3.98                                                                             4.22                                                                              oil                               9                                                                                    ##STR8##                                                                             ##STR9## 44.32                                                                            44.41                                                                             4.29                                                                             4.37                                                                              3.98                                                                             4.12                                                                              oil                               10                                                                                   ##STR10##                                                                           CH.sub.2 CClCH.sub.2                                                                    44.32                                                                            44.28                                                                             4.29                                                                             4.59                                                                              3.98                                                                             4.26                                                                              oil                               11    CH.sub.3                                                                              ##STR11##                                                                              40.75                                                                            40.88                                                                             3.41                                                                             3.48                                                                              4.31                                                                             4.50                                                                              oil                               12                                                                                   ##STR12##                                                                            ##STR13##                                                                              37.07                                                                            37.59                                                                             3.11                                                                             3.23                                                                              3.33                                                                             2.87                                                                              oil                               13    CH.sub.3                                                                              ##STR14##                                                                              40.75                                                                            41.19                                                                             3.41                                                                             3.50                                                                              4.31                                                                             4.15                                                                              oil                               __________________________________________________________________________

                  TABLE II                                                        ______________________________________                                         FUNGICIDAL ACTIVITY                                                          ACTIVITY IN TERMS OF % CONTROL                                                Compound                                                                      No.     GDM     TLB     CLB  TEB   BR   BPM   RB                              ______________________________________                                        1       100     81      98    0    0    0     --                              2       13      18      71   79    8    0     --                              3       13       0      71   97    8    0     --                              4       96      94      86   33    14   0     --                              5       86      29      --   50    --   --    --                              6       100     44      88   97    0    0     --                              7       99      97      23   74    0    0     --                              8       55      19      44   11    0    0     75                              9       74      31      92   11    0    0     75                              10      32      44      83   11    0    0     75                              11      68      48       8   69    0    0     95                              12      55      33      21   94    0    0     38                              13      90      59      30   100   0    0     69                              ______________________________________                                         GDM--Grape Downy Mildew (Plasmopara viticola)                                 TLB--Tomato Late Blight (Phytophthora infestans conidia)                      CLB--Celery Late Blight (Septoria apii)                                       TEB--Tomato Early Blight (Alternaria solani conidia)                          BR--Bean Rust Eradicant (Uromyces phaseoli tipica)                            BPM--Bean Powdery Mildew (Erysiphe polygoni)                                  RB--Rice Blast (Piricularia oryzae)                                      

What is claimed is:
 1. A method of controlling grape downy mildew causedby Plasmopara viticola fungi which comprises applying to the fungus orits habitat a fungicidally effective amount of a compound having theformula: ##STR15## wherein R and R¹ are independently substituted loweralkenyl having 2 through 6 carbon atoms and having 1 to 3 of the same ordifferent halogen substituents; and R⁴ is methyl or ethyl.